Digital pen



FIG. 1 is a front elevational view of a digital pen;

FIG. 2 is a rear elevational view thereof;

FIG. 3 is a left side elevational view thereof;

FIG. 4 is a right side elevational view thereof;

FIG. 5 is a top plan view thereof;

FIG. 6 is a bottom plan view thereof; and,

FIG. 7 is a front, bottom, and left side perspective view of a digital pen. 

CLAIM The ornamental design for a digital pen, as shown and described. 